Heater



FIG. 1 is a perspective view of a heater, showing our new design;

FIG. 2 is another perspective view thereof;

FIG. 3 is a front view thereof;

FIG. 4 is a rear view thereof;

FIG. 5 is a side view thereof;

FIG. 6 is another side view thereof;

FIG. 7 is a top view thereof; and,

FIG. 8 is a bottom view thereof.

The broken lines represent portions of the heater that form no part ofthe claimed design.

CLAIM The ornamental design for a heater, as shown and described.